We have recently made some changes to our submission system. If we receive a clinical trial, we will now ask that authors include the original trial protocol. Editor-in-chief, Dr Trish Groves, explains why:

Transparent reporting of research has always been at the heart of BMJ Open. From the very start the journal has published all research with open access, open peer review, and sometimes – when authors opt for sharing via the Dryad repository – open data.

Openness is specially important for clinical trials, and that’s why we are now requiring that trialists submit the study protocol to BMJ Open along with their paper:

• This should be the version of the protocol that gained ethics approval and was used to run the trial
• If the protocol was amended between getting ethics approval and starting the trial, the authors must say why in their cover letter
• The submitted protocol should be labelled with a version number and should include a history of substantive amendments, giving the dates when amended
• If the trial protocol has been published in an open access journal, and if that published version includes all the information and dates as listed above, then authors can simply provide BMJ Open with the reference and link to the published protocol
• If BMJ Open publishes the submitted trial, the protocol will be posted alongside as part of the pre-publication history

Why is BMJ Open now requiring protocols? For clinical trials (and protocols for clinical trials) BMJ Open has always required prospective registration, and we ask authors to give the trial’s registration ID in the paper’s abstract. This allows editors, peer reviewers, and ultimately readers to see a summary of the planned design of the trial and to compare it with the paper that reports the trial’s results. And dates in the registration record allow us to check that the trial was, indeed, registered prospectively – before any patients were enrolled. Isn’t this enough? Not quite. Trial registration provides a lot of useful information about a planned study, but registries have space only for a minimum of key information.

You can’t interpret the results of a clinical trial without fully understanding how the study was planned, designed, and conducted. Yet it’s all too common for methods to be reported selectively, partly, or not at all. And it has become clear that registration does not always prevent this, particularly when it comes to outcome switching.  Too often, prespecified outcomes are not reported, and others are added and reported in analyses that may not be valid. By making trial protocols available when trial results are reported in BMJ Open, we can all help to optimise the evidence base for treatments and other interventions.